No, proton mass cannot be measured directly. It can only be measured indirectly through experiments and calculations.
Proton mass is typically measured through high-energy particle accelerators, such as the Large Hadron Collider, which can collide protons at high speeds and measure the resulting energy and momentum of the particles.
Yes, proton mass can be calculated using other physical constants, such as the Planck constant and the speed of light, through the famous equation E=mc².
We cannot simply weigh a proton because it is too small to be measured on a standard scale. Additionally, the concept of weight is dependent on the gravitational force, which can vary in different locations and is not an accurate measurement of mass.
Inertia is the resistance of an object to changes in its motion. In the case of measuring proton mass, it plays a role in determining the energy and momentum of the particles during collisions, which is used to calculate the mass indirectly.